Need some info on filtering audio.

Hello, I am capturing a audio (baby's voice) with a mic. And I want to send it to arduino and then transmit it to a receiver wirelessly. So, I would like to know if I need to amplify the baby's voice and filter it in order to cancel out the background noise (it is a must to cancel out any background noise as much as possible).

See also - http://arduino.cc/forum/index.php/topic,74825.msg563760.html#msg563760 -